Drafting device



Aug. 12, 1969 A. J. FREY DRAFTING DEVICE Filed Jan. 24, 1968 Hrxriilxllnirl! l l lllll ll INVENTOR.

ARNOLD J. FREY TT R N YS United States Patent 3,460,261 DRAFTING DEVICEArnold J. Frey, 7434 Craigmere Drive, Cleveland, Ohio 44130 Filed Jan.24, 1968, Ser. No. 700,091 Int. Cl. B431 13/02 U.S. Cl. 33-75 4 ClaimsABSTRACT OF THE DISCLOSURE A drafting device including a frame-likesupport member having an opening, and an elongated rotatable membermounted on the support member and extending transversely of the openingfor relative rotational movement with respect to the support member. Thesupport member and rotational member include indicia adapted forselective registration for drawing and/ or determining angles. Both thesupport member and rotatable member include means associated therewithfor drawing and/or determining circles and straight lines, respectively.Measuring indicia is provided for determining the size and length of thecircles and lines, respectively. The rotational member can be flexed forinsertion in or removal from the support member.

BACKGROUND OF THE INVENTION This invention relates to drafting devices,and more particularly to protractors, rulers and circle drawinginstruments.

Heretofore, many types of protractors, rulers and circle drawinginstruments have been provided, but have not been found to be entirelysatisfactory. Some devices have been provided which may be used indrawing or determining angles, while other devices have been providedwhich may be used solely for drawing circles. Some other devices havebeen provided which serve as combined rulers and/or protractors and/orcircle drawing instruments, but these devices have been either extremelybulky, mechanically complex in construction, or have been relativelylimited in their use due to their structural arrangement.

SUMMARY OF THE INVENTION The present invention contemplates providing amultipurpose drafting device which is extremely simple in constructionhaving an extremely wide range of use and which comprises a frame-likesupport member having an opening defined by an endless marginal edge andan elongated rotatable member mounted on the support member and adaptedfor rotational movement with respect to the support member. The supportmember includes indicia means disposed adjacent the marginal edge whichare adapted for registration with indicia means disposed on therotatable member for selectively positioning the rotatable member withrespect to the support member. The rotatable member extends transverselyof the opening having the opposite ends thereof adapted for detachableconnection to the support member. The rotatable member includes web-likeportions adjacent the opposite ends which are adapted to slidably engagethe support member, thereby permitting the rotatable member to berotated over an angle of 360. The web portions include arcuate-shapedouter edges which define a circle having a diameter approximately equalto the diameter of the opening. In addition, the maximum thickness ofthe rotatable member is preferably less than the maximum thickness ofthe support member adjacent the opening, thereby to enable the rotatablemember to be rotated freely without inference as a result of engaging adrafting table or the like. The support member and the 3,460,261Patented Aug. 12, 1969 'ice rotatable member include at least onelinearly extending edge for drawing straight lines, and both areprovided with a plurality of apertures for inscribing circles of varyingdiameter. Measuring indicia is associated with the apertures and thelinearly extending edges for determining the size and length of thecircles and straight lines, respectively. The rotatable member isprovided with an undercut portion which may be utilized for lifting thedevice.

As will be seen, the drafting device of the present invention provides asimple, multipurpose instrument which is adaptable to a wide range ofuses. There is provided a single instrument which may be used fordrawing and/ or determining angles from zero to 360 withoutrepositioning the instrument and/or drawing or measuring linear lines,and/or drawing or determing circles having an extremely wide range ofdiameters, and/or plotting navigational courses. Furthermore, the novelconstruction permits the rotational member to be rotated relativelyunobstructed throughout an angle of 360 in addition to permitting theready removal and replacement of the rotational member without thenecessity to use external implements or devices, while eliminating thenecessity of fastening screws, clips, or the like, which have a tendencyto become lost or misplaced, rendering the device inoperable until suchare found or replaced. The device is preferably made from a polymericmaterial for economic, quality production.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation view ofthe drafting device of the present invention;

FIG. 2 is a cross-sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is an enlarged, partly cut away view of the connections betweenthe support member and rotatable member of FIG. 1; and

FIG. 5 is an enlarged, partly cutaway view of the rotatable member shownin FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drafting device of thepresent invention is shown generally at 10 in FIG. 1, and preferablycomprises a support member 12 having an opening 14 therein. An elongatedrotatable member 16 is provided which is mounted on the support member12 and extends transversely of the opening 14, The opening 14 is definedby an end- 1 e ss marginal edge 17 (FIG. 1) which is arranged toslidably engage the opposite ends of the rotatable member 16 to enablerotation of the rotatable member with respect to the support member 12,and which when flexed is readily removable from and replaceable on thesupport member 12, as desired. The rotatable member 16 is provided witha linearly extending edge 20 which extends approximately through thegeometric center, as at 22, of the opening 14, permitting the inscribingof a line which extends diametrically across the opening. The supportmember 12 and rotatable member 16 have indicia means 24 and 26,respectively, disposed thereon which are adapted for selectiveregistration with one another upon rotation of the rotatable member 16with respect to the support member 12 so that the angular relationshipof at least one pair of lines may be either drawn or determined.Aperture means, such as at 27 and 28, are provided in both the supportmember and rotatable member, respectively, for drawing circles. Asdimensional relationships are often critical when drafting ordetermining the size of an angle or a circle, both the support member 12and the rotatable member 16 are provided with linear measuring indicia,as at 29 and 31, respectively, to accomplish this end.

Referring to FIG. 1, the support member 12 comprises a frame-likestruture 13 which may be of any suitable configuration, but ispreferably generally rectangular in configuration when viewed in topelevation, as shown in FIG. 1, being defined by the linear top, bottomand side edges 30, 32, 34 and 36, respectively. Preferably the frame 13is substantially uniform in cross section, as shown in FIGS. 2 and 3,having an upper surface 37 and lower surface 38 which extendsubstantially parallel to one another. An opening 14, preferablycircular in configuration, as shown in FIG. 1, may be provided in theframe 13 which may have a geometric center 22 that is positionedequidistant between opposed of the respective edges 30, 32, 34 and 36.The opening 14 is defined by an endless annular projection 17, whichextends between the upper and lower surfaces 34 and 36, respectively.Preferably, the projection 17 is generally V-shaped in configuration, asshown in FIG. 4. The projection 17 may include an upper inclined edgesurface 18 and a lower inclined edge surface 19 which are inclinedtoward one another in a direction toward the opening 14 so as to mergeand form an endless marginal edge 41 for reasons which will becomeapparent hereinafter.

The rotatable member 16 comprises an elongated crossbar 42 which extendstransversely of and substantially entirely within the opening 14. Thecrossbar 42 includes an upper surface 64 and a lower surface 66 whichare substantially parallel to one another, as shown in FIG. 2. Thecrossbar 42 may be further defined by a first diametrically extendingedge 20 and a second edge 57 (FIG. 1) which extends generally parallelto the first edge 20 and spaced laterally therefrom. Preferably, thecrossbar 42 includes web-like portions 47 and 48 disposed adjacent theopposite ends thereof, and which are adaptable for detachable connectionto the projection 17 of the frame 13. Each of the web-like portions 47and 48 is preferably arcuate-shaped adjacent the opposed distal endswith such arcs together defining a circle concentric with the opening14.

As the recesses 54 and 56 are identical, only one, such as 54 (FIGS. 2and 4) of the web 47, will be described for purposes of illustrationwith corresponding features of the recess 56 being designated by likenumerals with the suffix prime being added thereto. Preferably, therecess 54 is disposed between the upper and lower surfaces 64 and 66,and is defined by the angularly disposed walls 40 and 50 which maycommence adjacent the upper and lower surfaces 64 and 66, respectively.The walls 40 and 50 may be inclined toward one another in a directiontoward the opposite end of the rotatable member 16 and merge with oneanother to form a pair of generally V- shaped projections 44 and 46adjacent the upper and lower surfaces 64 and 66, respectively, whenviewed in side elevation (FIG. 4), with each having an arcuateshapededge 35 and 45, respectively, defining the upper and lower extremitiesof the recess 54. The angle of inclination between the surfaces 40 and50 may be approximately the same as the angle of inclination of theinclined edge surfaces 18 and 19. Preferably, the edges 35 and 45 aredisposed in the plane of the upper and lower surfaces 64 and 66,respectively, and extend generally parallel to one another and with thediameter of the circle formed by the opposed arcs 35, 35' and 45, 45' ofthe web portions 47 and 48, respectively, being greater than the circleformed by the endless edge 41 of the projection 17. Preferably, thedimensional difference in the aforementioned diameter should be suchthat the surfaces 40 and 50 will be disposed in confronting relation tothe inclined edge surfaces 18 and 19 respectively, and be spaced apart asufiicient distance therefrom to permit relatively easy slidingengagement therebetween. Each of the webs 47 and 48 is provided withannular recesses 54 and 56, respectively, which are disposed between theupper and lower surfaces 64 and 66, and which are adapted to slidablyreceive portions of the projections 17 of the frame 13. Preferably, therecesses 54 and 56 are generally V- shaped in configuration, as shown inFIG. 4, and extend over a substantial portion of the arcuate length ofthe distal ends of the web portions 47 and 48. The edges 35, 35, 45 and45' are arranged to extend over only a segmental portion of the opening14 having a cord length between the opposite end edges 49, 51 and 53, 55of the web portions 47 and 48, respectively, greater than the transversewidth of the crossbar 42 between the edges 20 and 57 forming flangemembers 58, 59, and 60, 62 of the web portions 47 and 48, respectively.This arrangement provides for additional contact surface between theframe 13 and rotatable member 16 for supporting engagement therebetween.Furthermore, the foregoing arrangement permits the rotatable member 16to be readily removed from or replaced on the support member, whendesired. As the material of the crossbar 42 is resilient, removal may beaccomplished by pulling or pushing the crossbar 42 intermediate theopposed web portions 47 and 48 so as to cause the projection 17 to bepulled out of the recesses 54 and 56. To replace the rotatable member16, the projection 17 may be disposed in one of the recesses, such as54, and than the arm 42 may again be bent until the recess 56 ispositioned inside the opening so as to clear the projection 17 and inalignment therewith. When the arm 42 is released, the resiliency in thearm will cause the arm to straighten and the projection 17 may then beguided into the recess 56.

As previously indicated, the rotatable member 16 is substantiallyuniform in cross section, except as will be described hereinafter,having generally parallel upper and lower surfaces 64 and 66,respectively. Preferably, the maximum thickness of the rotatable member16 is less than the thickness of the support member 12 adjacent theprojection 17, to enable the rotatable member 16 to be rotated freelythroughout the entire circumferential length of the opening 14 withoutfrictional interference, except for the frictional engagement of theprojection 17 in the recesses 54 and 56, when the device 10 has theupper surface 37 or lower surface 38 in engagement with a supporting orworking surface, such as a drafting table or the like (not shown).

To indicate the size of an angle to be drawn or determined, indiciameans 24 and 26 are disposed on a frame 13 and the rotatable member 16adapted for selective registration with one another. The indicia means24 on the frame 13 preferably comprises any suitable scale to indicatethe 360 of a circle or any portion thereof. As shown, the marks orlines, such as at 67, extend radially outwardly adjacent the opening 14,and are circumferentially spaced in equal increments thereabout. Areference or zero degree lines 68 and 69 may be provided on oppositesides of the opening 14 defining an imaginary line which extendsparallel to the top and bottom edge of the frame 13. The rotatablemember 16 may be provided with reference lines 70 and 72 adjacent theedges 35, 45 and 35 and 45' of the web members 47 and 48, respectively,adapted for simultaneous registration with the lines 68 and 69,respectively. Lines 70 and 72 may be positioned on the rotatable member16, such that a line drawn along the edge 20 will extend diametricallythrough the geometric center 21 of the opening and the reference or zerodegree lines 68 or 69 when the lines 70 and 72 are in registration withthe lines 68 and 69, respectively. The point 21, indicated by the pointof the arrow 74 on the rotatable member -16, is preferably positionedequidistant from the endless marginal edge 17, therefore, the point ofthe arrow 74 will always be positioned at the geometic center 22 of thecircle regardless of the angular displacement of the rotational member16. By the foregoing arrangement, when the rotatable member 16 isrotated clockwise so that the reference line 70 is brought intoregistration with the line 67, the crossbar 42 will be rotated throughan angle of 45, as indicated by the scale 24. As previously indicated,the crossbar 42 may be rotated 360, and therefore, by placing the arm 42along one side of an angle with the point of the arrow 21 positioned atthe apex thereof, any angle from zero to 360 may be readily drawn ordetermined.

To determine the length of any particular line or distance, measuringindicia, such as at 33, may be disposed on either the top or bottomsurface and adjacent the linear edges 30, 32, 34 or 36 of the supportmember 12, and may comprise any suitable scale, such as inches orcentimeters, disposed along the edges 30 and 32, respectively (FIG. 1).As it may be necessary to measure the length of the line, such as theside of a triangle or the like without disturbing the position of thedrafting device 10, linear measuring indicia may, such as at 31, also beprovided on the crossbar 42 adjacent the edge 20. Preferably, the uppersurface of the support member 12 is tapered, as at 78 and 80, adjacentthe edges having measuring indicia associated therewith in a directiontoward the lower surface 38. Likewise, the upper surface 64 of thecrossbar 42, having linear measuring indicia 31 disposed thereon, may betapered adjacent the edge 20 in a direction away from the edge 57 andtoward the lower surface 66 to facilitate measuring accuracy.

Referring to FIG. 5, the crossbar 42 of the rotatable member -16 may bebeveled adjacent the edge 57 to provide a beveled surface 84. Thebeveled surface 84 may extend in a direction away from the lower surface66 and the diametrically extending edge 20 toward the upper surface 64terminating adjacent the edge 57. Preferably, the beveled surface 84terminates at the edge 85 between the upper surface 64 and the lowersurface 66 to provide an undercut portion which will enable the deviceto be readily lifted.

Referring again to FIG. 1, the aperture means 27 and 28 may be providedin the support member 12 and rotatable member 16, respectively, to drawcircles. The aperture means 27 on the support member 12 comprises aplurality of circular holes, a typical hole being designated at 86,which vary in diameter in any suitable increments, as desired. Forexample, and as shown in FIG. 1, ten holes may be provided in randomarrangement varying in diameter from inch, as at 86, to inch, as at 88.The aperture means 28 on the rotatable member 16 may comprise aplurality of apertures, such as at 89, which preferably are identical insize and are disposed in laterally spaced relationship lengthwise alongthe crossbar 42. To use the apertures 89, the rotatable member 16 may beflexed and removed from the support member 12. Then a pointed instrumentmay be inserted in one of the apertures to serve as the center of acircle and a pencil point may be inserted in any other selected aperturefor drawing a circle by rotating the member 16.

The terms and expressions which have been used are used as terms ofdescription and not of limitation, and there is no intension in the useof such terms and descriptions of excluding any equivalents of any ofthe features shown and described, or portions thereof, and it isrecognized that various modifications are possible within the scope ofthe invention claimed.

I claim:

1. A multipurpose, two-piece protractor-like drafting device for use indetermining and/or scribing angles, arcs and/or linear measurementscomprising, a generally flat frame-like support member, said supportmember having a centrally disposed circular opening defined by aninterior endless marginal edge disposed entirely within the confines ofsaid support member, an elongated, resilient rotor-like bar memberextending radially across and detachably mounted for rotation through360 within said Opening, said support member including an upper planarsurface and a lower planar surface adapted to be disposed in engagedrelation on a working surface, the minimum transverse thickness of saidsupport member adjacent said marginal edge being greater than themaximum thickness of said bar member to enable said bar member to beheld in spaced relation with respect to said working surface for freerotation thereof without substantial frictional interference with saidworking surface, said bar member including a pair of laterally spaced,oppositely disposed web-like portions made integral at the opposite endsthereof, said web-like portions extending generally at right angles withrespect to the longitudinal central axis of said bar member and eachhaving a segmental arcuate outer end edge for detachable interlockingsliding engagement with the interior marginal edge of the opening insaid support member, the arcuate outer end edges of said web-likeportion and said interior marginal edge being of a complementaryconstruction to provide a tongue and groove connection between saidsupport and bar members and with said bar member being sufficientlyresilient as to be bent and spring into snap action interfittingrelation to provide said connection, the maximum widthwise dimension ofsaid bar member being less than the corresponding widthwise dimension ofsaid web-like portions to facilitate said snap action, said bar memberhaving an inner side edge and an outer side edge extending transverselybetween said web-like portions with said side edge disposed to extendlinearly through the geometric center of said opening, said inner andouter side edges extending in continuous and uninterrupted relationbetween said web-like portions so that said bar member is supported insaid opening solely by said web-like portions, said support memberhaving scaled and circumferentially spaced indicia disposed adjacent theinterior marginal edge of said opening, and said bar member havingindicia elements thereon adapted for correlatable registration with theindicia on said support member upon selective rotation of said barmember for scribing angles and angular measurements in the assembledportion thereof, and adapted for use in bisecting angles when removedfrom such assembly, indicia means disposed adjacent said inner linearextending edge for drafing lines of selective length, said cross-barmember includes uniform diameter apertures therein adapted to receivethe marking end of a transcribing member, said uniform diameterapertures disposed in spaced relation lengthwise of said cross-barmember for inscribing circles upon rotation thereof and wherein anundercut portion is provided on the outer side edge of the bar memberfor lifting the device.

2. A drafting device in accordance with claim 1, wherein said web-likeportions each include a pair of spaced,

oppositely disposed flange portions disposed inwardly of the respectivearcuate end edges thereof, said flange portions made integral andextending outwardly from opposed sides of said cross-bar member and inlaterally offset relation with respect to one another, and the juncturesof the respective flange portions with said cross-bar member adjacentsaid outer side edge being substantially greater in a width-wisedirection as compared to the corresponding junctures of the otherrespective flange portions adjacent the inner side edge of saidcross-bar member. 3. A drafting device in accordance with claim 1,wherein the indicia means on said cross-bar member includes an indiciaelement disposed adjacent said inner side edge at the geometric centerof said opening, and at least one other indicia element disposed on arespective one of said web-like portions disposed in generally parallelalignment with said inner side edge for selective registration with theindicia means on said support member. 4. A drafting device in accordancewith claim 1, including aperture means disposed in said support memberfor inscribing circles,

said aperture means comprising circular holes of vary- 2,428,699 10/1947Ebert et a1. 33110 ing diameter. 2,560,736 7/1951 Olson 33104 ReferencesCited 7 6 FofElGN PATENTS 4 ,099 3/ 195 Great Britain. UNITED STATESPATENTS 5 6,291 4/1893 Switzerland. 411,741 9/1889 Dow 3375 507,216 10/1893 Colby 3375 HARRY N. HAROIAN, Primary Examiner 509,335 11/1893Stowell 33107 556,582 3/1896 Maier 33107 U.S. Cl. X.R. 1,058,474 4/1913Sharpe 3397 10 3327, 104

1,154,673 9/1915 Vanness 3375

